name: Publish Docker Image
on:
  push:
    branches:
      - main
    tags:
      - v*
env:
  IMAGE_NAME: peterevans/dockerhub-description
jobs:
  publish:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2

      - name: Docker Hub login
        run: echo "${{ secrets.DOCKERHUB_PASSWORD }}" | docker login -u "${{ secrets.DOCKERHUB_USERNAME }}" --password-stdin

      - name: Push image to Docker Hub
        run: |
          # Strip git ref prefix from version
          VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')

          # Strip "v" prefix from tag name
          [[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION | sed -e 's/^v//')

          # Use Docker `latest` tag convention
          [ "$VERSION" == "main" ] && VERSION=latest

          # Build and tag image
          docker build . --file Dockerfile --tag $IMAGE_NAME --label "org.opencontainers.image.version=$VERSION"
          docker tag $IMAGE_NAME $IMAGE_NAME:$VERSION

          # Tag with the minor version if valid
          MINOR_VERSION=$(echo $VERSION | sed -n "s/^\([0-9]*.[0-9]*\).[0-9]*$/\1/p")
          [[ ${#MINOR_VERSION} -gt 0 ]] && docker tag $IMAGE_NAME $IMAGE_NAME:$MINOR_VERSION
          # Tag with the major version if valid
          MAJOR_VERSION=$(echo $VERSION | sed -n "s/^\([0-9]*\).[0-9]*.[0-9]*$/\1/p")
          [[ ${#MAJOR_VERSION} -gt 0 ]] && docker tag $IMAGE_NAME $IMAGE_NAME:$MAJOR_VERSION

          docker push $IMAGE_NAME